1. Field of the Invention
The present invention relates to a device combining magnetic resonance imaging (MRI) and positron emission tomography (PET) for a breast examination. The device comprises a PET scanner ring disposed in a narrow place of a breast MRI bed in order to precisely examine the breasts and acquire better images within a short time.
2. Description of Related Art
Generally, both magnetic resonance imaging (MRI) and positron emission tomography (PET) examinations are required for a subject to assist physicians in the clinical diagnosis and judgment. Magnetic resonance imaging is used to investigate the anatomy and detailed location of subjects' bodies, and positron emission tomography (PET) provides information of cell physiology and metabolism. However, there are some disadvantages respectively existed in these two medical imaging techniques, i.e. MRI is unable to offer metabolic information and disease status and PET is in lack of showing anatomy and detailed location. Moreover, these two imaging examinations cost high and take a lot of subject's time and energy in each inspection. To improve the above mentioned problems, in 2006, Philips Co. brought forward a shared and fast moveable examination bed for connecting MRI and PET to obtain complete images of a subjects' whole body. After the subject is examined by one of the two inspections, he or she can be moved instantly to receive the other one inspection. However, the move of the subject results in the image distortion, so the images need further corrections.
Currently, some researchers incorporate MRI and PET imaging for allowing a subject to be examined by both inspections simultaneously. In this technique, one must ensure in advance that both PET and relevant parts for a combination of PET and MRI can operate normally in the environments with a strong magnetic attraction and an electromagnetic interference caused by MRI. For instance, in 2010, Siemens Co. replaced the light sensitive element (a.k.a. photomultiplier, PMT) of PET with avalanche photodiodes which are unaffected by magnetic fields, so as to solve the problem of mutual influence between MRI and PET. Therefore, the Siemens PET/MRI system allows two tests to run simultaneously without moving a patient to a different scanning system. Although Siemens Co. has developed the PET/MRI system for examining subjects' whole bodies, combining a PET with a breast MRI still has a problem, i.e. difficulty in accommodating a PET machine due to the small space of a breast MRI system.